The environmental impact statement comes to Israel: An initial assessment

Despite obstacles inherent in the structure of government and the lack of a strong national constituency, environmental impact assessment became a policy-making element in the government of Israel in 1982. The Environmental Protection Service formed in 1973 now needs to develop strategies to promote environmental awareness and environmentally informed decision making among the public, private and public developers, and within the Ministry of the Interior.     

Evaluating forest management practices using a GIS-based cellular automata modeling approach with multispectral imagery

The objective of this study was to develop an integrated geographic information system (GIS) cellular automata (CA) model for simulating insect-induced tree mortality patterns in order to evaluate the influence of different forest management activities to control insect outbreaks. High-resolution multispectral images were used to determine susceptibility of trees to attack, whereas the GIS-based CA model simulated the effectiveness of clear-cuts and thinning practices for reducing insect-induced tree mortality. The results indicate that thinning susceptible forests should be more effective than clear-cutting for reducing tree loss to insect outbreaks. This study demonstrates the benefits of an integrated approach for understanding and evaluating forest management activities and expresses the need for spatial analysis and modeling for improving forest management practices.     

公共场所人员应急疏散引导研究

在公共场所应急疏散的过程中,应急疏散人员往往需要更多地依靠自身经验,而非传统的完全理性决策。为解决这一问题,提出一种具有引导者的多主体系统人员应急疏散交互模型,对模型中的Agent进行分类,建立单独Agent、结伴Agent和引导者Agent三类群体Agent,对疏散人员在引导者的指挥和控制作用下进行模拟。仿真结果表明在应急管理中设置引导者,可以在疏散初始阶段引领疏散人员快速明确疏散目标,减少迂回现象;疏散过程中合理疏导人群利用疏散出口,避免某一出口过度拥堵;引导者在疏散过程中进行密度控制,可以使整个疏散过程更合理有序,整体提高疏散效率。     

Accumulation trends of metals and a metalloid in the freshwater crayfish Astacus leptodactylus from Lake Yeniçağa (Turkey)

This study aims to determine the extent of metal pollution in Lake Yeniça?a (Bolu, Turkey) by investigating the accumulation trends of five metals (Al, Cu, Fe, Ni and Zn) and a metalloid (As) in gills, exoskeleton, hepatopancreas and abdominal muscles of the freshwater crayfish Astacus leptodactylus. Principal component analysis (PCA), cluster analysis (CA), correlation analysis and analysis of variance (ANOVA) were utilised to determine the accumulation profiles of each element over four seasons. The greatest element accumulation was found to occur in the gills. All elements in exoskeletal tissue displayed positive correlations with each other, a similar trend was also observed in the hepatopancreas samples. Strong (r=0.868) and very strong (r=0.960) positive correlations were found between the accumulations of Al and Fe in gills and the exoskeleton, respectively. Correlations in tissue accumulation rates are discussed in the context of metabolic roles and impacts associated with the elements tested. Elemental compositions of Yeniça?a water and sediment samples were also investigated to determine whether the composition of the surrounding environment matches the metal accumulation trends of tissue samples. We demonstrate that, by the criteria set by the United States Environmental Protection Agency, Lake Yeniça?a is heavily polluted in terms of As and Ni.     

类脂/醋酸纤维素复合吸附材料的制备与性能

采用相转化法将类脂包埋到醋酸纤维素(CA)中,制备出了具有对水中低剂量亲脂性有机污染物高效吸附去除的平板膜.以扫描电子显微镜观察了复合材料的结构形貌和表面特征.利用机械搅拌方式和超声方式对类脂进行分散的实验表明,超声对类脂的均匀分散具有强化作用.同时考察了铸膜温度(室温、0℃)对类脂分散的效果,表明低温有助于形成小的脂滴.另外,通过复合膜的红外谱图证实,类脂和CA属于物理混合,不会改变类脂的分子结构,从而不会影响类脂对亲脂性有机污染物的吸附性能.通过荧光分析法分析复合膜在正己烷溶剂中的稳定情况,表明类脂已被完好地包埋到膜中,因而在去除有机污染物的过程中不会从复合膜中渗出.     

证据理论在港口航行环境安全组合评价中的应用

为解决不同方法用于港口航行环境的安全评价产生的结果不一致问题,利用证据理论善于发挥各评价方法的特性映射机理不同的长处,整合和协调相关证据的信息,获得最接近事实的评价结果。以中国沿海10个港口的航行环境安全程度为例,应用证据理论,把主成分分析法、因子分析法、逼近理想解排序法(Topsis)、模糊理论及灰色理论5种方法所得评价结果,作为支持航行安全的证据进行组合处理。所得结果经相关性检验并与原文献中众数理论组合评价结果作比较,其结果一致性较高。船长们认为基于证据理论的组合评价结果更符合实际,确认该方法可以在同类研究中普遍应用。     

吐温20吸附改性聚乙烯膜改善MBR抗污染性能

通过物理吸附Tween20对聚乙烯中空纤维微孔膜(polyethylene hollow fiber microporous membranes,PEHFMM)进行表面改性。衰减全反射傅立叶变换红外光谱(attenuated total reflection Fourier transform infrared spectroscopy,FT-IR/ATR)和场发射扫描电子显微镜(field emission scanning electron microscopy,FE-SEM)观察结果表明:吐温20有效地吸附到了PEHFMM上。采用停滴法测定水接触角(contact angle,CA)以表征膜表面的亲水性。数据显示:30℃时随着吸附量的增加膜的水接触角先降后升并出现最低值;40℃吸附时水接触角则单值下降直至稳定。为建立吸附量与膜生物反应器(membrane bioreactor,MBR)中膜污染作用之间的关系,使用人工污水进行了活性污泥过滤实验。结果发现:吐温20吸附量大约是100～200μmol/g时可以明显地提高膜在MBR中的抗污染能力。     

基于红外吸收法的哈龙替代灭火剂HFC－125的浓度监测技术

HFC-125(五氟乙烷)有较好性能,可替代哈龙灭火剂应用于飞机灭火系统中。在飞机灭火系统的评估实验中,模拟地面或是飞行状态,灭火剂浓度测量设备都是必不可少的。基于非色散红外光谱技术(NDIR),初步设计了HFC-125灭火剂浓度监测设备,该设备采用硅碳红外光源,入射光经过斩波器调制转变为交变光,通过单光路测量气室后,被碲镉汞红外探测器转化为电压信号并被前置放大电路放大。通过电压比与体积分数的对应关系,可以实现对HFC-125浓度的监测。     

连续曝气模式下同步硝化反硝化的持续稳定性

为研究反应周期内同步硝化反硝化(SND)过程的持续稳定性,试验以模拟城市污水为研究对象,于恒定气量连续曝气的SBR反应器内,在反应周期内恒定不同曝气量的条件下,考察氮转化规律和DO、ORP及pH的变化规律。结果表明,SND持续稳定的时间和TN去除率随曝气量的增加而减少和降低,DO、ORP和pH曲线上出现的折点可预示SND过程的结束和完全硝化反应的开始,而pH曲线上的"谷点"可预示硝化反应的结束。由此可知,在恒定气量连续曝气模式下,SND的持续稳定时间是有限的,不能延续到反应周期结束,但可用DO、ORP和pH值作为SND过程持续稳定程度的控制参数。